What is the characteristic equation for an=5an−2a_n = 5a_{n-2}an=5an−2?
r2−5=0r^2 - 5 = 0r2−5=0
r2+5=0r^2 + 5 = 0r2+5=0
r−5=0r - 5 = 0r−5=0
r2−5r=0r^2 - 5r = 0r2−5r=0